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ENCODING

Base64 Decoder

Decode a Base64 string back to text.

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What this tool does

A Base64 string pasted on the left decodes back to its original text on the right, live — the reverse of encoding, recovering exactly the bytes that were encoded in the first place.

Getting the original text back correctly

If the encoded text originally contained anything outside plain ASCII — an emoji, an accented letter, a non-Latin character — the decoded bytes are read back as real UTF-8 rather than assumed to be one character per byte, so the original text comes back exactly as it was rather than garbled.

What happens with invalid input

Not every string of letters and numbers is valid Base64 — it uses a specific 64-character alphabet plus = padding, and has to be a length that alphabet actually produces. Pasting something that does not fit those rules is reported clearly rather than silently returning the wrong result.

Privacy

Decoding happens in your browser. Nothing you paste is sent to a server.

FAQ

Frequently asked questions

Is my data uploaded anywhere?
No. Decoding happens locally in the browser — nothing is sent to a server.
Why does decoding fail on some pasted text?
Base64 uses a specific 64-character alphabet plus = padding, and the input length has to match what that alphabet actually produces. Text with characters outside that alphabet, or an invalid length, is not valid Base64 and cannot be decoded as-is.
Will emoji or accented characters decode back correctly?
Yes — decoding reads the bytes back as real UTF-8 rather than assuming one byte per character, so text that originally contained emoji, accented letters, or non-Latin scripts comes back exactly as it was encoded.
Can this decode Base64 that came from an image or another binary file?
The decoded bytes are interpreted as text here, so a Base64 string that actually represents an image or another binary file will not produce a readable result -- it needs a tool that decodes straight to a downloadable file instead of text.
Does whitespace in the pasted Base64 cause a problem?
Leading and trailing whitespace around the pasted text is trimmed automatically before decoding.
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